Pc web shovel ahd deedge



- Dec. 22, 1925- 1,566,585

I G. R. DEMPSTER POWER S HOVEL AND DREDGE Filed Jan. 20, 1922 4 Sheets-Sheet 1 Dec. 22 1925- 1,566,585

G. R. DEMPSTER POWER SHOVEL AND DREDGE Filed Jan. 20, 1922 4 Sheets-Sheet 2 Deco G. R. DEMPSTER POWER SHOVEL AND DREDGE Filed Jan. 20, 1922 4 Sheets-Sheet 3 Dec; 22, 1925' V G. R. DEMPSTER POWER SHOVEL AND DREDGE Filed Jan.\20, 1922 4 Sheets-Sheet 4 Patented Dec. 22, 1925.

. UN'ITEQ GEORGE E; DEMPSTERQ 0F KNOXVILLE. TENNESSEE.

POWER SHOVEL AND DREDGE.

Application, filed-January 20,1922. Serial No. 530,627.

To a l-whom it may concern: I

Be it known that I, Gnonen R. Dnmrsrrnn, a citizen of the United gtates, residing. at Knoxville, in the county of Knox and State of Tennessee, have invented a new and useful Improvement in Power, Shovels and Dredges, of which the following is a speci: fication, reference being had to the accompanying drawing.

My improvement relates particularly, to such power actuated shovels and dredges as embody a boom and a dipper and a stem or stick which is applied to the boom to adapt it for hinge movement whereby the dipper israised and lowered and also adapt it for endwisc movement whereby the dip per is moved toward and from the boom,

and the dipper having a h nged bottom door which is held in the closed position by a latch which is to be released by drawing arope or cable after the dipper has taken its load and has been swung into position for discharging its load. Y

Formerly the rope or cable used for releasing the latch was drawn manually. The object of my invention is to provide an improved mechanism including a motor, for

. drawing such cable for the release of the latch. Such power shovels and dredges have been made larger and larger, from time to time, in order that the clippers may take larger loads. lhus the latch mechanism has oecome larger and its engagement made stronger, and consequently a larger force is needed to disengage the latch mechanism, so

l by, hand power. Yet it is essential -.e latch he released promptly and rehly and immediately upon thev arrival'of dipper in the discharging position. Hence effort is being made to produce a satisfactory power mechanism for releasing these latches.

In the accompanying drawings,

Fig. 1 is an elevation of the boom, dipper, dipper stick and associated parts of a steam she-rel of dipper has hinged bottom controlled by latch;

Fig. 2 is a side elevation of my irotor and drum structure;

3 is an upright section of the motor and drum structure;

Fig. 3 is anenlarged fragmentary trans..-

large to make it difficult to release the' the ordinary type in which the verse section through the upper, part of the transmission ring,

Fig. 4 is a section on the line, H, of Fig. 3,1ooking toward the left;

Fig. 5 is an upright section on the, line, 55, of Fig.v 3, loOkingtOWard the left;

Fig. 6 is an upright, section on the line, 6-6, of Fig. 3, looking toward the left;

Fig. 7. is an uprightfsection on the line, 77,' of Fig. 3, looking toward the left;

Fig. 8 is adetail section showing the attachment of, the latch cable to the drum. Referring tosaid drawings, in is the boom of'an ordinary steam shovel. A is the dipper stem or stick. A? is the dipper supportedat the outer end of the dipper stick. A is the dipper door hinged to the dipper in the usual manner. A is a member of a dipper door latch of any ordinary form for controlling said door. A cable, A engages the dipper from the upper end of the boom for raising and lowering the dipper and the outer end of the dipper stick.

Shipper mechanism, B, is mountedon the boom for shifting the dipper stick, A endwise to shift the dipper toward and from the boom.. This mechanism may be of any ordinary form used for this purpose. It comprises a main horizontal; shipper shaft, B on which is a spur gear wheel (not shown) meshing with a gear rack on the dipper stick. In my improved apparatus, in the form shown by the drawings,a combined motor and drum structure are applied rigidly to one end of the shipper shaft, B so that said structure must rotate simultaneously with the shipper shaftwhen th latter rotates.

C is the shaft of the motor and drum structure. @no end, C of said shaft is screwthreaded and is seated in the interiorly screw-threaded end of: the shipper shaft, B said two shafts being thus immovably joined to each other, so. that the shaft, 0, is rotated whenever the shaft, B is rotated for shifting the dipper stick, A endwise in either'direction. The purpose of such rotation of the'shaft, C, is to cause the rotation of the drum whenever the dipper stick is shifted endwise, as will be described further on.

D is the drum. This loosely surrounds the shaft, C, and has flanges, D Between, the dang 1" ithas spiral groove, D to receive a latch rope or cable, D being wound on the drum. At the left of the drum the shaft, C, is screw-threaded and receives a nut, C to prevent the drumfrom moving leftward.

Rightward movement of the drum is prevented by the piston structure. Said structure has a hub, E surrounding the shaft, C, and held against movement thereon by a tongue or key, E and a set-bolt, E From said hub a piston arm, E extends radially outward near and parallel to the adjacent end of the drum. At its outer end said arm supports a piston stem, E, which is concentric to the shaft, C. At its end opposite the arm, E the piston stem terminates in a piston head, E the right hand face of whichrests against the adjacent face of the adjacent drum flange, D During the relative rotations of the drum and the piston, said piston head slides on said face of said drum flange. The hub, arm, stem and piston head are shown as a-singl'e casting. A'collar, E is threaded around the outer or right hand end of the hub, E of the piston struc ture, said collar being fitted to beheld inimovably on the hub. At the left hand part of said collar is a circumferential channel, E which receives one member, F, of a steam admission ring. Said member, F, is plane to which the shaft, C,

' is perpendicular, and said member is even with the left hand face of the collar, E. A

' channel, E corresponding in reverse to the channel, E is formed on the hub,'E near the arm, E, of the piston structure. In said channel is seated the secmd member, F of the steam admission ring. Said member extends radially outward, from said channel and is then flanged rightward to .meet the outer part of the adjacent radial face of the ring member, F. Cap screws, extend through the member, F, into the member, F to .imniovably bind said members to each other. Theseating of said members in the channels, E and Eflis to be suthciently loose to permit easy turning of the piston struce hub in said ring, and yet the joint becen said ring and said hub should be made as close as is permissible, in order that the escape of steam along said joints may be brought to a minimum. Adjacent the left hand face of the member, an annular seat, F is formed for a packing ring, F which extends over the joint between the .iember, F and the hub, E At the left of the inner part of the member, F a similar annular seat F is formed on said hub. A packing ring,

.Fflrests on said seat and extends across the joint between the member, T and the hub, On the opposing faces of said'pac ring rings and opposite each other are lugs E which enter the ends of panding coiled spring, Fi which serves to press said rings sidewise against the adjacent members the admission ring and the adjacent faces of the hub, The function of said packing rings is to further limit the escape of steam through screw-threaded to receive the exteriorly screw-threaded steam delivery pipe F Said pipe is to lead from a source of steam supply and is to be suitably secured against movement, whereby the admission ring is also held against movement. Hence said ring does not rotate during the rotations oft-he shaft, C, and the piston structure.

The steam port, F opens into the annular passage, F formed between the fiange'of the ring member, 1 and the packing rings, F and F (Figs. 8, 3 and 6). A steam passage, F extends from the passage, F through the piston arm, E, and through the piston stem, E and through the piston arm,

E and through the piston head, E

Thus, regardless of the rotation of the piston structure (while as above stated, the admission ring and steam delivery pipe are stationary), there is communication between the steam passage in the piston stem and the steam passage in the admission ring. Thus it will be seen that there is at all times a I continuous steam passage from the steam deliverypipe through the admission ring and the piston structure hub and the piston arm and the piston stem and the piston head, the discharge being through the free end of said head. a v

The piston head and the piston stem enter a cylinder having two walls, G and one will, G The wall, G is in a plane to which the shaft, C, is perpendicular. The walls, G are concentric to said shaft and their left hand edges bear against the adjacent face of the adjacent drum flange, D

Ca screws G extend from the ri 'ht 7 I u a through the walls, G into said drum flange,

whereby said walls are firmly bound to said flange. The walls, G and G and said drum flange form a chamber which is rectangular in cross section and concentric to the shaft, C; and said chamber is of the same'cross section as the piston head, E, and is at the same distance-from the axis of' the shaft, C. Hence said chamberis adapted to receive the piston head and piston stem and permit the sliding of said head in said chamber. The end of said chamber which is adjacent the piston arm, E is open. The other end of said chamber is closed'by an end wall, G which is transverse to the walls, G and G and approximately radial to the shaft, C.

It will now be seen that if steam is ads mitted through the steam delivery pipe, F, the steam will follow the passages above described" and discharge from the} piston I "headi into he 'cl0sed endbf thecylinder [chamber and force the cylinder into niove ;ment' away frond-thepistonjhead', it being rememberedthat the, entire piston structure is fixedon the shaft, C, and the "drum','on which the cylinder isflsupported, being loose to the piston structure, a sto ,H, is seated on the outer face of the rig 't hand drum. flange, D in position todneet-"the piston arm, E t,"andin position to be arrestedby fsaid arm When the piston head is inftheop'enf and free to rotate on said shaft. besen that'the action of the steam for'the turi1i1 1 ofthe cylinder anddrum is limited to -one directionand to only apart of one rotation of the drum, Hence the steam'm'o tor Whichis thus combined Withjthe drum isadapted to draw the latch cable through only'a short -distance,;the distance required for releasing the latch I The latch cable,-D extends'from the drimi to the movable latch member, A andfsaid cable may be secured to the drum in any desiredmanner. The drawings show it" ex tending through the aperture, D in the right hand drum flange and thence under a;

clamping plate, D which is secured to said flange'by a bolt, D

To limit the turning of; the drum relative end otthe cylinder. To reduce shoclrvvhen said stopymeetsfsa'id arm,;'a socket is formed in the, stop toJopen1towardsaid arm, and ,a

coiledspring, H is f seatedin saidfsocket" and made to project-therefrom-tovvard the piston arm to make impa'ct therewith-f j For the controlj'of steam in'the delivery pipe, F athreeay valve, F (Fig: l)'is.

placed on" said pipe toiservefor admitting steam into the-admission rln'g'and also to cut off such admission an d allow exhaust from said ring, whereby-the drum may're-- verse until the forward end-ct the piston head'meets the end Wall, G ot th'e cylinder;

Inpractice it has been found that/the force exerted on the latch cab1e,-:D while the a door is swinging into the closedposition is sufficient to cause said cable to thusreverse the drum through the necessary fractional turn. I The foregoing description of the operation ofmy-appara'tus relates only to the action ,of the motor, that action being "limited to the turning of the drum-only as [far as is needed in connection with the releasing and;

reengaging of the latch.

' When the dipper stick, 7 endWise on the boom by the 'turning'ot the shipper mechanism'shatt, E the shaft, C,

and all the m'echanism supported thereby are correspondingly rotated for Winding the latch cable on or unwinding it from the drumin harmony with the movement ofthe dippertorvard or away from the-shafts, B f andfl, whereby thet-=length of-saidcable be ItWill also I shaft,' .C,as far as the piston permits. But

A is being shifted:

release ofthe latch When there is no steam; cylinder tiveen the; latch and the, drum isQsubstaiif-f-"i {many maintained, in order that fat any time the partial'rotation, given; by 'the motor to;

the dmmxwill-d'r yv theflatchqcable tor'tlie and the-entire structureis beingftiirned, the cli-um"-inay be turned independently of the such turning off the-drum-isonly fractional and does not nterfere with the winding and unwinding ofthe drum duringgthe 'IOJCHIIOII of the entire 3 structure by the rotationof I theishipper shaft-,- B

claim as my invention,

the combination with a; dipper-supporting structure comprising a'boom and aidippfer stick shiitable QIldWlSBQOll said; boom, and

a. dipper supported on 'said'stick and com-.

prising; a closing member to be released for discharging the load, and rotary means for 38a an apparatus of the kiiidgles'cribed,

shifting the dipper, stick endwisefon the l.foo1n ,of;a cablehavingone end in operative-relation ,with said closing member,

means concentricwith the axis of said shiftng *ineansj for taking up ,and" paying out said cable approximately. synchronously c with the endwis'e movements ofithedipperL stick, and an operator-controlled motor concentric with said-axis for pulling said cable ifer actuating saidiclos'ing member, substane' ti a} if; described 2; l'n'anf apparatus-of the kindlldescribed, the combination with a dipper stick, means ior shitting the dipper stick endwise, and a dipper supported on the dipper stick-and vcompi sing a, closing member to be released ici discharging the dipperloadfo'fva drum and drum structure sha'ft rotatable approxi- :ely synchronously With the endtvise VGHlelltSO-f the dipper stick, a fluid motor inder concentric-With thej'drum axi s and a i n and fixed on 'said'sha'ft for partially turn ed to'the ene a piston concentric ,TWith" ing said drum indep'eiridently offsaidsynchronous; rotation-of the drum, and acable j having one end in operative relation with SiUtl closing member and having its other end attached toi's'a'id drum, substantiallyv as described. .1

In an apparatus of the kind described, I

combination Witha dipper stick, means I the dipper stick-,"a hollow piston motor co; 1='( ;en-tric Withthedrum axis for partially I V turning .saidfdru'n independently or said] s cncl'ironous rotation of the drum, and-1 a; cable-ha vi 11g one end in operative relation with said. closing member and having its other end attached to said drum, substan tially as described. V 7

l. In an apparatus of the kind described, the combination with a dipper stick, means tor shitting the dipper stick endwise, and a dipper supported on the dipper stick and comprising a closing member to be released for discharging the dipper load, of a drum supported by said shifting means for rotation approximately synchronously with the endwise'movements of the dipper stick, a motor concentricwith the drum axis for partially turning said drum independently of said synchronous rotation of the drum,

' and arable having oneend in operative relation with said closing member and having its other end attached to said drum,

substantially as described. I

5. In an apparatus of the kind described,

the combination with a dipper stick and means'comprising a shaft for shifting the dipper stick endwise, and a dipper supported on the dipper stick and comprising a closing member to be released for discharging the dipper load, of a drum supported by said shaft for rotation approximatelyv syn- V chronously With the endwise movements of the dip er stick, a motor having one member fixed on the drum andhaving the other member fixed'on said shaft for partially turning said drum independently of said synchronous rotation of the drum, and a ,cable having one end in operative relation tary structure comprising a drum and motor,

the motor comprisinga piston structure hub 7 end a stationary admission ring surrounding said hub, and the drum and motor, ex-' ccpting the admission ring, being rotatable approximately synchronously with the endwisemovements of the dipper stick, the motor serving for partially turning said drum independently of said synchronous rotation of the drum, and a cable having one end in operative relation with said closing memher and having its other end attached to said drum, substantially as described. I

7. In an apparatus of the kind described, the combination with a dipper stick, means for shifting the dipper stick endwise, and a dipper supported on the dipper stick and comprising a closing member to be released for discharging the dipper load,'of a rotary structure comprising a drum-and an oscillating motor concentric with the drum axis and comprising a stationary admission ring, and

proximately synchronously with the end- 7 Wise movements of the dipper stick, the motor serving for partiallyturning said drum independently of saidsynchronous rotation of the drum, and-a cable having one end in operative relation with said closing member and having its other end attached to said drum, substantially as described.

8. In an apparatus ofthe kind described, the combination with a dipper stick a shaft, means on said shaft for shifting the dipper stick endwise, and a dipper supported on the dipper stick and comprising a closing member to be released for discharging the dipper load, of a'drum supported by said shifting means for rotation approximately synchronously with the endwise movements of the dipper stick, a motor comprising a piston fixed on said shaft and a cylinder forming a part of the drum structure, the

latter being on the drum and the function of which motor is to partially turn said drumindependently of said synchronous 'rotation of'the drum, and a cable having one end in operative relationvvith said closing member. and having its other end attached to said drum, substantially as described;

9. In an apparatus of thekind described, the combination.with a dipper stick, means for shifting the dipper stick endwise, and a dipper supported on the dipper stick and comprising a closingmemberto be released for discharging the dipper load, of a' drum supported by said shifting means for ,rotation I approximately synchronously with the endwise movements of the dipper stick, a motorcomprising a piston and a cylinder which is on the drum and one wall of which is formed by the end of the drum and the function of which motor is to partially turn said drum independently of said synchronous rotation of the drum, and a cable having one end in operative relation With said closing member and having its other end attached to said drum, substantially as described.v

10. In an apparatus of the kind described, the combination with a dipper stick, means for shifting the dipper stick endwise, and a dipper supported on the dipper stick and comprising a closing member to be released for discharging the dipper load, of a drum supported by said shifting, means for rotation approximately synchronously With the endWise movements of the dipper stick, a motor comprising a cylinder concentric with the axis of the drum and a curved pis ton extending into said cylinder and having a passage opening through the inner end of the piston, the function of said motor being to partially turn said drum independently of said synchronous rotation of the drum,

and a cable having oneend in operative re-' 7 stantially' as described.

' shaft, a-cylinder 0n thedrunn' a piston rigid:

1 1. In an apparatus of the kind described;

the combination with a dipper stick, means, including a rotary shaft, for'shifting the: dipper stick end Wise, and a dipper supported-on the dipper ,stick and comprising a; closing member to'be releasedfor discharg -f ing the dipper load, of a drum loose on-said tn said shaftancl extending into -s aid eylin- I ment of the drum and the piston, and a cable. having one end in {operative relation with said le'l osingmember and "having itsother "end attached to saidjdrum', substantially as} 'clescribed;

In, asa ony whereel: I have sig a my I 'ff name, this 3lst, daylOf December, in the year 7 0 gneth'ous and nine hundred and twenty-one"? i j 1 ORGER. DEMPSTER.

der, means for limiting-the relative n10ve-' 7 

